Drill-like driving device

ABSTRACT

A driving device including a right-angle handpiece assembly having a casing containing an input shaft, an output shaft and means drivingly connecting same. A bone drill attachment is connectible to the handpiece assembly and includes a cylindrical extension mountable upon the output end of the casing and concentric inner and outer drill bits which project from said extension. The inner drill bit is connectible to the output shaft by a pair of clutch mechanisms which are normally spring-biased into a disconnected position. The outer drill bit normally rotates with the inner drill bit but is permitted to move axially and angularly relative to the inner drill bit through a predetermined distance. The cutting end of the inner drill bit extends axially beyond the cutting end of the outer drill bit. Alternately, a wire driving attachment can be connected to the handpiece assembly and includes a chuck structure mountable upon the output end of the casing and drivingly connectible to the output shaft. The chuck structure has a continuous opening therethrough which aligns with a through opening in the casing for receiving therein an elongated member, such as a wire.

United States Patent Crim et al.

DRILL-LIKE DRIVING DEVICE Inventors: Paul E. Crim, Portage; Wayne IWarfield, Kalamazoo Township, Kalamazoo County, both of Mich.

[73] Stryker Corporation, Kalamazoo,

Mich.

Filed: Dec. 27, 1973 Appl. No.: 428,843

Related US. Application Data Division of Ser. No. 229,680, Feb. 28,1972, Pat, No. 3,797,497.

Assignee:

References Cited UNITED STATES PATENTS 11/1941 Cox et al. 128/3102,495,691 1/1950 Brennan 74/365 S 3,678,934 7/1972 Warfield et al.128/310 X FOREIGN PATENTS OR APPLICATIONS 781,511 8/1957 United Kingdom128/310 51 May 13, 1975 Primary Examiner-Benjamin W. Wyche Attorney,Agent, or Firm-Woodhams, Blanchard and Flynn [57] ABSTRACT A drivingdevice including a right-angle handpiece as sembly having a casingcontaining an input shaft, an output shaft and means drivinglyconnecting same. A bone drill attachment is connectible to the handpieceassembly and includes a cylindrical extension mountable upon the outputend of the casing and concentric inner and outer drill bits whichproject from said extension. The inner drill bit is connectible to theoutput shaft by a pair of clutch mechanisms which are normallyspring-biased into a disconnected position. The outer drill bit normallyrotates with the inner drill bit but is permitted to move axially andangul arly relative to the inner drill bit through a predetermineddistance. The cutting end of the inner drill bit extends axially beyondthe cutting end of the outer drill bit. Alternately, a wire drivingattachment can be connected to the handpiece assembly and includes achuck structure mountable upon the output end of the casing anddrivingly connectible to the output shaft. The chuck structure has acontinuous opening therethrough which aligns with a through opening inthe casing for receiving therein an elongated member, such as a wire.

4 Claims, 9 Drawing Figures THEMED RAY I 3 33. 5

SHEET 10F 3 a 3 6 N6 6 S sw 5 mm D 3 3 DRILL-LIKE DRIVING DEVICE This isa division, of application Ser. No. 229,680 filed Feb. 28, 1972, now US.Pat. No. 3,797,497.

FIELD OF THE INVENTION This invention relates in general to a drill-likedriving device and, in particular, to an improved device which includesa right-angle handpiece assembly which can have several differentattachments mounted thereon, such as a bone drilling attachment or awire driving attachment for permitting drilling or perforation of a bonein a human or other animate.

BACKGROUND OF THE INVENTION A number of drills and drill bits have beendeveloped in the past for the purpose of providing openings in bonestructure, such as the skull, and a drill bit construction of this typeis disclosed in the G. W. Smith US. Pat. No. 2,842,131. The purpose ofthis drill structure is to perform the drilling operation with a minimumof bone damage and without perforating the meninges so that the braintissues under the meninges will not be contaminated with bone fragmentsproduced during the drilling operation.

I-Ieretofore, however, it has been the common practice to furnish adrill bit assembly, as shown in the aforementioned Smith patent, whichis driven by a driver or handpiece, not especially adapted for this typeof surgical operation. Moreover, insofar as I am aware, no completedrill assembly has been furnished for easy connection to an operation bya highspeed air motor and having the features of automaticallydisconnectible clutch means as well as a right-angle drive.

Accordingly, the primary object of this invention is the provision of adrill device having clutch means for automatically disconnecting a pairof concentric drill bits from the source of rotational power and,moreover, having a simple means for disconnecting the drill bits fromthe handpiece.

A further object of this invention is the provision of a drill devicehaving a handpiece which can be quickly and easily adapted for otheruses, such as a wire driver, thereby reducing inventories required forassembling different types of surgical instruments.

Other objects and purposes of this invention will become apparent topersons familiar with this type of equipment upon reading the followingdescriptive matter and examining the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective viewof the improved handpiece assembly constructed according to the presentinvention.

FIG. 2 is a central, cross-sectional view of the handpiece assembly.

FIG. 3 is a side elevational view illustrating therein the handpieceassembly of FIG. 2 having a bone drill attachment mounted thereon.

FIG. 4 is an exploded, perspective view of the bone drill attachment ofFIG. 3 and illustrating its relationship to the handpiece.

FIG. 5 is a central, sectional view of the bone drill attachment andillustrating the manner in which same is mounted on the output end ofthe handpiece assembly, the bone drill attachment being illustrated inits released or nondriving position.

FIG. 6 is a central, sectional view similar to FIG. 5 and illustratingthe bone drill attachment in its engaged driving condition.

FIG. 7 is a fragmentary, sectional view illustrating the operationalposition of the bone drill when it breaks through a large bone, such asa cranial bone.

FIG. 8 is a sectional view taken along the line VIII- -VIII of FIG. 5.

FIG. 9 is a side elevational view, partially in cross section,illustrating the improved handpiece assembly of FIG. 2 having a wiredriving attachment mounted thereon.

For convenience in reference only, the terms upper, lower, rightward"and leftward" will have reference to the device and parts thereof,particularly as appearing in FIGS. 2, 3, 5 and 9. The terms output andinput will have reference to the lower end and right end, respectively,as appearing in FIGS. 2, 3 and 9. The terms inner and outer will havereference to the geometric center of the device and designated partsthereof. Said terminology will include the words above specificallymentioned, derivatives thereof and words of similar import.

SUMMARY OF THE INVENTION The objects and purposes of the invention,including those set forth above, have been met by providing a drill-likedriving device which includes an improved right-angle handpiece assemblyhaving input and output shafts arranged within a casing at right anglesto each other and interconnected by gear means. The input shaft includesa reduction gear assembly therein whereby the input shaft can beconnected to a highspeed air motor and the output shaft can be driven ata low rotational speed. The handpiece assembly is connectible to a bonedrill attachment which is mountable on the output end of the casing andincludes drive shaft means which is drivingly connectible to the outputshaft of the handpiece assembly. The drive shaft means of the bone drillattachment includes a pair of normally disconnected clutch assembliesconnected in series between the output shaft of the handpiece assemblyand a pair of concentric drill bits. The drill bits are normally rotatedtogether but are mounted for permitting limited axial and annulardisplacement therebetween for permitting the rotation of the drill bitsto be stopped under emergency situations wherein the clutch assembliesdo not release. Alternatively, the handpiece can have a wire drivingattachment mounted on the output end thereof, which wire drivingattachment in one embodiment comprises a chuck mounted on the casing andhaving a wire engaging member connected to the output shaft forpermitting rotation of an elongated wire, which wire extends through thechuck and the casing for permitting driving of a wire of substantiallength.

DETAILED DESCRIPTION FIGS. 1 and 2 illustrate therein the improved rightangle handpiece assembly 11 of the present invention, which assembly isdesigned to permit its use with several different drill-likeattachments. The handpiece assembly 11 is particularly sutiable for usewith a bone drill attachment 12, as illustrated in FIG. 3. However, thehandpiece assembly 11 can also be utilized with a wire drivingattachment 13 as illustrated in FIG. 9.

Considering first the handpiece assembly 11, as illustrated in FIGS. 1and 2, same includes a substantially T-shaped casing 16 having anelongated tubular handle 17 fixedly connected to an elongated tubulargear housing 18. The gear housing 18, for purposes of convenience, isconstructed of two pieces and includes a main housing part 19 and an endcap 21 which is fixedly, here threadedly, connected to the upper end ofthe main housing part 19. The gear housing 18 has a coaxial cylindricalopening 22 extending therethrough, which opening has cylindricalportions 23 and 24 of re duced diameter at the opposite ends thereof.The end of the housing 18 opposite the end cap 21 is also formed with areduced cylindrical hub 26 on the exterior thereof which is formed witha flat 27 thereon. Gear housing 18 also has a further opening 28provided in the side thereof and partially defined by an outwardlyextending circular boss 29 which, in the illustrated embodiment, isthreaded to permit same to be fixedly connected to the handle 17. Theopening 28 is thus substantially aligned with a central opening 31 whichextends longitudinally of the handle 17.

The gear housing 18 has a drive or output shaft 32 supported forrotation therein by bushings 34 and 36 disposed adjacent the oppositeends of the gear housing. The drive shaft 32 is of tubular constructionand has a central opening 33 extending axially throughout the completelength thereof. The opposite ends of the tubular drive shaft 32 areprovided with enlarged internal recesses 37 which result in theformation of an axially facing shoulder 38. The tubular drive shaft 32,in the region of each recess 37, is provided with a pair ofdiametrically opposite slots 39 which are of a substantially L-shapedconfiguration and extend axially inwardly from the free ends of theshaft. THe enlarged recesses 37 and slots 39 thus function as half of aconventional bayonet-type coupling for permitting either end of thedrive shaft 32 to be drivingly coupled to a further shaft or member.

A driven face gear 41 is concentrically disposed within the opening 22of the gear housing 18, which face gear 41 is positioned in surroundingrelationship to and is nonrotatably connected to the drive shaft 32 byany conventional means, such as a key 42. The face gear 41 is rotatablysupported on the gear housing 18 by means of an intermediate thrustbearing 43.

Considering now the handle 17, same includes an input shaft assemblyrotatably supported therein and provided for drivingly connecting theoutput shaft 32 to an external source, such as an air motor. The inputshaft assembly includes an input shaft 46 substantially coaxiallydisposed within the opening 31 and rotatably supported within the handle17 by conventional antifriction bearings 47. The ball bearings 47 aresupported on an annular bearing retainer 48 which has one end thereoffixedly connected to a speed reducer housing 49 by a conventional setscrew 51. The housing 49 contains therein a conventional planetarygear-type speed reducer which has a rotatable drive shaft 52 drivinglyconnected to the input shaft 46 by means of ah intermediate coupling 53.A conventional speed reducer 54 is drivingly connected between the shaft52 and a driven shaft 55. The driven shaft 55 has a spur gear 56nonrotatably secured thereto. Gear 56 has axially elongated teeth formedon the periphery thereof and functions as a drive gear, being disposedin continuous meshing engagement with the driven face gear 41.

The speed reducer housing 49 has an annular shoulder or flange 57 formedthereon, which flange is clampingly held between the boss 29 and aninternal shoulder formed in the handle 17 for fixedly securing the speedreducer housing 49 in position within the handle. The input shaft 46 isprovided with a conventional slotted coupling portion 58 on the free endthereof adapted to engage the output end of a suitable drive mechanismor power source, such as a flexible drive member connected to an airmotor, not illustrated.

Considering now the bone drill attachment 12, as illustrated in FIG. 4,same includes a housing assembly 61 which is adapted to be connected tothe handpiece assembly 11. The housing assembly 61 has disposed thereinfirst and second clutch assemblies 62 and 63 connected in series withone another, with the second clutch assembly 63 in turn being drivinglyconnectible to a clutch drive shaft assembly 64. The latter in turn isdrivingly connected to a cutter assembly 66.

Referring now to FIGS. 5 and 6, the housing assembly 61 includes acylindrical extension sleeve 67 having an enlarged upper section 68 ofsufficient inside diameter to telescope over the cylindrical hub 26. Theextension sleeve 67 is releasably connected to the handpiece casing by aset screw 69 which engages the flat 27 formed on the casing. Anelongated cylindrical bushing 71 is secured within the central portionof the extension sleeve 67, as by means of a press fit, and a furtherannular bushing 72 is secured within the upper end of the extensionsleeve 67. The bushings 71 and 72 respectively rotatably support thesecond and first clutch assemblies 63 and 62.

The first clutch assembly 62 includes a sleevelike rear clutch element73 rotatably supported within the bushing 72 and having a tubular shaft74 fixedly secured, as by being press-fitted, within the interiorthereof. The upper end of shaft 74 extends upwardly beyond the clutchelement 73 so as to be insertable into the internal recess 37 formed inthe end of the drive shaft 32. The upper end of the tubular shaft 74 hasa pair of diametrically opposed flanges or ribs 76 extending radiallyoutwardly therefrom and adapted to be slidably received within theelongated straight portions of the slots 39 formed within the driveshaft 32. An ejector pin 77 is slidably supported within the extendsthrough the tubular shaft 74 and has an enlarged stop or abutment 78fixedly secured to the upper end thereof, with a further abutment 79being fixedly secured to the lower end thereof. A conventionalcompression spring 81 is disposed in surrounding relationship to theejector pin 77 and is confined between the tubular shaft 74 and thelower abutment 79 for normally urging the ejector pin 77 in a downwarddirectron.

The rear clutch assembly 61 also has a pair of clutch projections,namely a pair of diametrically opposed pins 82, fixedly secured to andprojecting downwardly from the lower end of the clutch element 73. Thepins 82 are adapted to coact with the second clutch assembly 63 forpermitting same to be clutchably engaged with and drivingly connected tothe first clutch assembly 62. The second clutch assembly 63 includes asleevelike front clutch element 83 rotatably supported within thebushing 71 and having a slot 84 extending diametrically across the upperaxial end face thereof. An elongated key 86 of substantially rectangularcross section is fixedly positioned, as by being press-fitted, withinthe slot 84 and is disposed so as to be normally abuttingly engaged bythe lower end of the ejector pin 77 associated with the first clutchassembly 62. The front clutch element 83 has a central opening 87extending therethrough, the lower end of which is enlarged. A retainersleeve 88 is disposed within the lower end of the opening 87 and isfixedly secured to the front clutch element 83. An elongated ejector pin89 is disposed within the opening 87 and is slidably supported by theretainer sleeve 88 and the clutch element 83. Ejector pin 89 isresiliently urged downwardly by a compression spring 91 and projectsbeyond the retainer sleeve 88. The spring 91 is disposed within theenlarged portion of the opening 87 and is confined between the clutchelement 83 and a collar 92 which is fixedly secured to the ejector pin89 intermediate the ends thereof.

The second clutch assembly 63 also has clutch projections, namely a pairof diametrically opposed clutch pins 93, fixedly secured to andprojecting axially downwardly from the lower end of the front clutchelement 83. The clutch pins 93 are disposed for clutching engagementwith the clutch drive shaft assembly 64.

The clutch drive shaft assembly 64 includes a sleeve like drive shaft 96on which is press-fitted a surrounding sleeve 97, which sleeve isrotatably supported within an annular bushing 98. Bushing 98 isstationarily disposed witihin a surrounding cuplike end cap 99 which isdisposed within the lower end of the cylindrical extension sleeve 67 andis fixedly secured thereto, as by a pin 101.

The clutch drive shaft 96 has an annular flange 102 adjacent the upperend thereof, which flange has a slot 103 extending diametrically acrossthe upper axial end face thereof. An elongated key 104 of substantiallyrectangular cross section is fixedly disposed within the slot, as bybeing press-fitted therein, and is positioned so as to be abuttinglyengaged by the lower end of the ejector pin 89. The clutch drive shaft96 also has a central opening 106 formed therein, which opening permitsreception therein of a portion of the cutter assembly 66.

Considering now the cutter assembly 66, same includes an inner cutter ordrill bit 107 and an outer tubular cutter or drill bit 108 rotatablysupported on the inner cutter 107. The outer cutter has a small helicalslot 109 formed in the sidewall thereof and through which extends a pin,namely a screw 111. The screw 111 is fixedly secured to the inner cutter107 and extends radially outwardly thereof. The slot-and-pin connectionprovides the only direct driving connection between the cutters, whileit also permits the outer cutter 108 to have a limited rotational andaxial displacement relative to the inner cutter 107.

The outer cutter 108 has an annular flange 112 at the rearward endthereof which is adapted to move into abutting engagement with the lowerend of the bushing 98, whereas downward movement of the outer cutter 108is limited by an annular flange 113 which is provided on the lower endof the inner cutter 107, which inner cutter projects axially downwardlybeyond the lowermost end of the outer cutter 108. The lower axial endfaces of the inner and outer cutters are both provided with cuttingedges and surfaces which are conventional and thus further descriptionthereof is not believed necessary.

To permit the cutter assembly 66 to be drivingly connected to the clutchdrive shaft assembly 64, the inner cutter 107 is provided with anelongated shank portion which is adapted to be slidably inserted intothe opening 106 formed within the clutch drive shaft 96. The upper freeend of the inner cutter 107 has a substantial flat formed thereon whichresults in the formation of an upwardly extending projection 114 havinga cross section approximating or slightly greater than half a cylinder.This projection 114 is adapted to align with the axially overlap a key116 which is fixedly secured to the drive shaft 96. The key 116 has across sectional profile which is substantially equal to or slightly lessthan half of a cylinder, so that the key 116 and the projection 114 thussubstantially comprise a cylinder when overlapped to thus provide arotatable driving relationship between the shaft 96 and the inner cutter107. The cutter 107 also has a friction ring 117 disposed in surroundingrelationship therewith and positioned for frictionally engaging theinner periphery of the drive shaft 96 for holding the shank of the innercutter 107 within the drive shaft 96.

OPERATION The operation of the drilling device 10, particularly when thebone drill attachment 12 has been attached to the handpiece assembly 11,will be briefly described to insure a complete understanding thereof.

Prior to operational use, the bone drill attachment 12 is secured to thehandpiece assembly 11 by positioning the large end 68 of the cylindricalextension sleeve 67 over the cylindrical hub 26, the bone drillattachment being secured to the handpiece by the set screw 69. Asuitable power source is drivingly connected, as by a flexible powertransmitting element, to the coupling portion 58 of the handpiece inputshaft 46. This thus provides a power transmitting drive connectionbetween the input shaft 46 of the handpiece and the rear clutch element73 of the bone drill attachment 12.

After the bone drill attachment 12 has been secured to the handpiece 11,the cutter assembly 66 is disposed in a disengaged or nonrotatableposition since all of the clutches in the bone drill attachment arereleased, being in the position illustrated in FIG. 5. The spring 81 ofthe first clutch assembly causes the ejected pin 77 to be resilientlyurged downwardly so that the lower end of the pin engages the key 86,whereby the ejector pin 77 pushes the second clutch assembly 63downwardly within the bushing 71 so that the clutch pins 82 are axiallyspaced and disengaged from the key 86. The ejector pin 89 of the secondclutch assembly is also resiliently urged donwardly by the spring 91 sothat the lower end of the pin 89 engages the key 104 and pushes theclutch shaft assembly 64 downwardly so that the key 104 is also axiallyspaced and disengaged from the clutch pins 93. The downward movement ofthe clutch shaft assembly 64 also causes the inner cutter 107 to be inits lowermost or fully extended position, as illustrated in FIG. 5. Theouter cutter assembly 108, being connected to the inner cutter 107solely by the pin and slot connection 109 and 111, will be disposedadjacent the flange 113 or adjacent the bushing 98, depending upon theorientation of the overall drilling assembly, since the cutter 108 willmove axially of the cutter 107 due to the effect of its own weight. Theinitial position of the cutter 108, when the device is inoperative, isimmaterial to the successful operation of the drilling apparatus.

When adrilling operationis to be performed, the drill assembly 10 ispositioned, as shown in FIG. 6, so that the lower end of the innercutter 107 engages the surface of a bone 121, such as a cranial bone.The drive shaft 32 of the handpiece assembly may now be rotated byenergizing the external power source which is attached to the couplingportion 58. By pressing downwardly on the handle 17, the cutter assembly66 is moved upwardly until the outer cutter 108 substantially engagesthe lower end of the bushing 98. This upward movement of the cutterassembly also causes the clutch shaft assembly 64 to be slidably movedupwardly in opposition to the urging of the spring 91, whereby theejector pin 99 is depressed in an upward direction so that the key 104thus moves into a position wherein it is disposed between and axiallyoverlaps the clutch pins 93. This thus results in the second clutchassembly 63 and the clutch shaft assembly 64 being substantiallynonrotatably interconnected. Downward pressing on the handle 17 alsocauses the second clutch assembly 63 to be moved upwardly toward thefirst clutch assembly 62 in opposition to the urging of the spring 81,whereby ejector pin 77 is thus depressed to permit the key 86 to bepositioned between and in axially overlapping relationship with theclutch pins 82. This thus results in the first clutch assembly beingnonrotatably and drivingly connected to the second clutch assembly.Since the first clutch assembly is in turn nonrotatably connected to thedrive shaft 32 due to the engagement of the flanges 76 within thebayonet slots 39, the rotation of the drive shaft 32 is thus transmittedto the inner cutter 107 causing rotation of same. The pin 111 secured tothe cutter 107 in turn causes a corresponding rotation of the outercutter 108.

When the drilling operation is being performed on the bone 121, the bonedrill attachment is disposed in driving engagement substantially asillustrated in FIG. 6. Since the inner cutter 107 extends below theouter cutter 108, the inner cutter performs the initial cuttingoperation and results in the formation of a hole of a predetermineddiameter, which hole is then subsequently enlarged by the rotation ofthe outer cutter 108. The hole is thus drilled in a two-step sequencedue to the axial spacing between the inner and outer cutters. THedrilling will continue, due to the urging of the operator, until theinner cutter 107 cuts through the bone, as illustrated in FIG. 7.However, the outer cutter 108 has not yet fully cut through the bone 121and is thus supported on a narrow annular shelf of bone 123. Due to thedownward pressure of the operator on the handle 17, and due to theengagement of the outer cutter 108 with the bone shelf 123, asubstantial frictional torsional resistance is imposed on the outercutter 108, whereas substantially no torsional resistance is imposed onthe cutter 107 since it has passed through the bone 121. Accordingly,the driving torque imposed on inner cutter 107 causes the pin 111 toengage the side of the slot 109, thereby causing the inner cutter 107 tobe cammed downwardly into the position illustrated in FIG. 7, whichdownward camming of the inner cutter 107 also permits the two clutchconnections to be disconnected due to the resilient urging of thesprings 81 and 91. The transmission of torque to the inner cutter isthus substantially instantly terminated. Further, since the outer drillbit 108 is still supported on the bone shelf 123, this thus prevents theinner and outer cutters from being pressed inwardly, thereby preventingan inadvertent puncturing of the meninges 122 which covers the brain.

While the operation as described above results in the disconnection ofthe inner cutter 107 due to the camming action created by the pin andslot 109 and 111, nevertheless the termination of torque transmission tothe inner cutter 107 may also occur due to the urging of the springs 81or 91. Particularly, when the inner cutter 107 initially cuts completelythrough the bone 121, the springs 81 or 91 may then possess sufficientforce to cause the inner cutter 107 to be extended to thus drivinglydisconnect one or both of the clutch connections. Whether the springscause the actual initial disconnection of the clutch assemblies, orwhether the initial downward movement of the cutter 107 is caused by thepin-and-slot arrangement, depends upon the size of the springs and theamount of friction possessed by the overall device. However, it will bereadily apparent that the pin-and-slot connection and the clutch springseffectively function as backup systems for one another so that one orthe other will initially release, whereupon failure of one of thedevices to release will in turn result in the release of the other.Further, while only a single clutch could be provided, the provision oftwo clutch devices also provides a safety feature in that if one clutchdevice fails to release, the other clutch device will release to insurestoppage of the drill. The present invention thus provides threedisconnectible couplings connected in series to positively insure thatthe cutting bits will be positively stopped as soon as the inner cutterpenetrates the cranial bone to thus prevent puncturing of the meningeswhich covers the brain.

MODIFICATION FIG. 9 illustrates therein a modification of the presentinvention wherein the handpiece assembly 11 of FIGS. 1 and 2 is providedwith a wire driving attachment 13 mounted thereon. Particularly, in theillustrated embodiment, the wire driving attachment 13 substantiallycomprises a conventional Jacobs chuck which has a chuck body 131rotatably mounted within a sleevelike body 128 whidh is mounted on andsecured to the cylindrical hub portion 26 of the handpiece casing by aset screw 128. The chuck body 131 supports therein an annular jawactuating member 132. A plurality of circumferentially spaced andradially movable jaws 133 are mounted within the member 132 and areactuated in a conventional manner for permitting the jaws to be radiallymoved into clamping engagement with an elongated member, such as anelongated wire 137. The chuck body 131 also has a hollow shaft portion134 extending from the rearward end thereof, which shaft portion isadapted to extend into the end of the drive shaft 32 and is providedwith one or more radially projecting pins 136 thereon which extends intothe bayonet slots 39 for nonrotatably connecting the chuck body 131 andthe jaws 133 to the drive shaft 32.

In the operation of the wire driving device illustrated in FIG. 9, thewire 137, which is generally of an elongated length, is extended throughthe opening 33 formed in the drive shaft 32 and is clamped by the jaws133 so that a predetermined length of wire extends outwardly from thejaws. Upon operation of the device, whereupon the rotation of the driveshaft 32 is transmitted to the jaws 133, the wire is operatedsubstantially as a drill and is rotatably drilled into a bone. After thepredetermined length of wire has been drilled into the bone, the chuckis released and the overall device lifted upwardly to permit a furtheramount of wire to pass through the chuck, whereupon the chuck is thenagain retightened onto the wire and a further length of wire is thendrilled into the bone. THis preccdure is repeated until the desiredlength of wire has been inserted into the bone.

Thus, as is apparent from the above-described structure and operation,the handpiece ll of the present invention, as illustrated in FIGS. 1 and2, is highly desirable since it can be utilized interchangeably withmany different types of attachments, such as the bone drill attachmentand the wire driving attachment. Further, while the above descriptionhas illustrated the attachments as mounted on one end of the drive shaft32, it will be readily apparent that all of the attachments couldlikewise be secured to the handpiece so as to be drivingly connected tothe opposite end of the drive shaft 32 (the upper end in FIG. 2),thereby permitting rotation of a tool or driven element in the oppositedirection. The desirable handpiece thus is interchangeable in that theattachments can be attached to the opposite ends of the drive shaft tothus permit a driven element to be rotated in opposite directions.

Although a particular preferred embodiment of the invention has beendisclosed in detail for illustrative purposes, it will be recognizedthat variations or modifications of the disclosed apparatus, inlcudingthe rearrangement of parts, lie within the scope of the presentinvention.

The embodiments of the invention in which an exclusive property orprivilage is claimed are defined as follows:

l. A drill-like driving assembly, comprising:

substantially T-shaped casing means having a main housing part and ahandle part fixedly secured to said main housing part at a locationdisposed intermediate the ends thereof, said main housing part and saidhandle part comprising elongated tubular members disposed with theirlongitudinally extending axes positioned to substantially intersect oneanother at substantially right angles;

input means rotatably supported within the interior of said handle part,said input means having a rotatable coupling member disposed adjacentthe free end of said handle part adapted for connection to an externalpower source;

elongated output shaft means rotatably disposed within and extendinglongitudinally of said main housing part, said output shaft means havingan opening extending continuously therethrough in a directionsubstantially parallel to the longitudinally extending direction of saidmain housing part, said output shaft means also having first and secondtorque transmitting coupling portions provided thereon adjacent theopposite free ends thereof;

gear means drivingly connected between said input means and said outputshaft means for transmitting rotation therebetween, said gear meansbeing disposed adjacent the junction of said main housing part and saidhandle part and including first and second meshing gear members mountedfor rotation about axes substantially perpendicular to one another; and

driven means detachably connectible to said output shaft means androtatable thereby, said driven means including a stationary housingmember releasably attached to said casing means and driven shaft meansrotatably supported within said housing member, said driven shaft meansincluding means for releasably and nonrotatably engaging a workingelement, said driven shaft means also having coupling means associatedtherewith and re leasably engageable with one of said first and secondcoupling portions for drivingly connecting said driven shaft means tosaid output shaft means.

2. A drill-like driving assembly according to claim 1, wherein saidinput means includes first and second shaft parts and a reduction gearassembly connected to and between said first and second shaft parts forproducing a substantial differential between the rotational speeds ofthe first and secoind shaft parts, the second shaft part being connectedto said gear means.

3. A drill-like driving assembly according to claim 1, wherein saiddriven means includes jaw means disposed for engaging an elongatedrodlike element, such as a wire.

4. A drill-like driving assembly according to claim 1, wherein the firstand second coupling portions are provided adjacent the opposite ends ofsaid output shaft means, each coupling portion including a pair ofsubstantially diametrically opposed, axially elongated slots extendingaxially inwardly from the free end of said output shaft means, and saiddriven shaft means having an end portion adapted to be slidably disposedwithin the interior of said output shaft means and having a radiallyextending projection adapted to extend into at least one of said slotsfor nonrotatably coupling said driven shaft means to said output shaftmeans.

1. A drill-like driving assembly, comprising: substantially T-shapedcasing means having a main housing part and a handle part fixedlysecured to said main housing part at a location disposed intermediatethe ends thereof, said main housing part and said handle part comprisingelongated tubular members disposed with their longitudinally extendingaxes positioned to substantially intersect one another at substantiallyright angles; input means rotatably supported within the interior ofsaid handle part, said input means having a rotatable coupling memberdisposed adjacent the free end of said handle part adapted forconnection to an external power source; elongated output shaft meansrotatably disposed within and extending longitudinally of said mainhousing part, said output shaft means having an opening extendingcontinuously therethrough in a direction substantially parallel to thelongitudinally extending direction of said main housing part, saidoutput shaft means also having first and second torque transmittingcoupling portions provided thereon adjacent the opposite free endsthereof; gear means drivingly connected between said input means andsaid output shaft means for transmitting rotation therebetween, saidgear means being disposed adjacent the junction of said main housingpart and said handle part and including first and second meshing gearmembers mounted for rotation about axes substantially perpendicular toone another; and driven means detachably connectible to said outputshaft means and rotatable thereby, said driven means including astationary housing member releasably attached to said casing means anddriven shaft means rotatably supported within said housing member, saiddriven shaft means including means for releasably and nonrotatablyengaging a working element, said driven shaft means also having couplingmeans associated therewith and releasably engageable with one of saidfirst and second coupling portions for drivingly connecting said drivenshaft means to said output shaft means.
 2. A drill-like driving assemblyaccording to claim 1, wherein said input means includes first and secondshaft parts and a reduction gear assembly connected to and between saidfirst and second shaft parts for producing a substantial differentialbetween the rotational speeds of the first and secoind shaft parts, thesecond shaft part being connected to said gear means.
 3. A drill-likedriving assembly according to claim 1, wherein said driven meansincludes jaw means disposed for engaging an elongated rodlike element,such as a wire.
 4. A drill-like driving assembly according to claim 1,wherein the first and second coupling portions are provided adjacent theopposite ends of said output shaft means, each coupling portionincluding a pair of substantially diametrically opposed, axiallyelongated slots extending axially inwardly from the free end of saidoutput shaft means, and said driven shaft means having an end portionadapted to be slidably disposed within the interior of said output shaftmeans and having a radially extending projection adapted to extend intoat least one of said slots for nonrotatably coupling said driven shaftmeans to said output shaft means.